JPH03180886A - Light transmission type liquid crystal display device - Google Patents

Abstract

PURPOSE:To reduce the thickness and to perform all operation with one light source by using an optical fiber which has a light leak surface and a fiber plane light source which has a reflecting surface and a light source. CONSTITUTION:The light emitted by the light source 5 passes through optical fibers 3 which are bundled to reach the reverse surface of transmission type liquid crystal 6. The optical fibers 3 have the light leak surface at this part, so light leaks out of the optical fibers 3 and is irradiated by the reflecting surface 4 to irradiate the reverse surface of the transmission type liquid crystal 6. Each optical fiber 3 can be manufactured in thin structured because of its property, so the thickness of the band-like bundled optical fiber 3 is reducible. Since the reflecting surface 4 can be made in thin, the thickness of the illumination light source 5 is reducible. Further, the transmission loss of the optical fibers 3 is small, so only one light source 5 is required.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid crystal display equipped with a backlight.
In particular, the present invention relates to a liquid crystal display suitable for a water heater remote control.

[Prior Art] As shown in FIG. 6, a light transmission type liquid crystal display B used for a water heater remote control has a light guide 200 with a reflective surface made of plastic arranged on the back side of a transmission type liquid crystal 100. It was illuminated by several light emitting diodes 300.

[Problem to be solved by the invention] However, the conventional technology has the following drawbacks.

(A) Since the light guide 200 is thick, the space 210 below the liquid crystal display 100 cannot be used effectively, and the remote control case 400 needs to be thick.

(i) Since the light guide 200 has a lot of transmission loss, several light emitting diodes 300 were required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a light transmission type liquid crystal display that can be made thinner and requires only one light source.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a transmissive liquid crystal that displays information such as numbers, characters, symbols, figures, images, etc. by time-division drive, and a rear surface of this liquid crystal. In a transparent layer liquid crystal display device, the illumination source includes optical fibers bundled in a band shape and having a light leakage surface, a reflective surface formed on the back surface, and an optical fiber arranged at the end of the optical fiber. The configuration uses a fiber surface light source with an attached light source.

[Action and effect of invention] The present invention has the following functions and effects.

(1) The light emitted from the light source passes through optical fibers bundled in a band shape and reaches the back surface of the transmissive liquid crystal. The optical fiber in this area has a light leakage surface, so light leaks out of the fiber and is reflected by the reflective surface, illuminating the back side of the transmissive liquid crystal. Here, since each optical fiber can be manufactured to be thin due to its nature, the thickness of the optical fibers bundled into a band is thin. Further, the reflective surface can also be formed thin. Therefore, the thickness of the illumination source becomes thinner.

(2) Due to its nature, optical fibers have low transmission loss and only require one light source.

[Example 1] As a first example of the present invention, a remote control for a water heater using a transparent hot water layer liquid crystal display will be explained based on FIG.

A water heater remote control A has a transparent hot water layer liquid crystal display 2 disposed inside a remote control case 1.

The remote control case l is box-shaped (15mm x 100mm x 20
0 mm) and is made of plastic. A display window 11 (40 mm x 100 mm) is formed at the upper right of the surface, into which a transparent resin 12 is fitted. Furthermore, a hidden lid 13 is hinged to the left end. Reference numeral 14 indicates operation keys for setting, and reference numeral 15 indicates operation keys that are frequently used. Is there a connection end on the left side of this case 1? - (not shown) is provided,
It is connected to the water heater body using a 2-wire wire.

Incidentally, the power supply of the remote control and the control signal are superimposed on the two-wire wire.

The transparent liquid crystal display device 2 comprises an optical fiber bundle 3, a reflective tape 4, a light emitter 5 attached to the end of the optical fiber bundle 3, and a liquid crystal 6 (as shown in FIG. 2).

The optical fiber bundle 3 is made by bundling optical fibers 31 having a fiber diameter of 0.251 nm into a plurality of tubes, and has a width of 40 mm. The optical fiber 31 is a known one, and consists of a core 32 made of methacrylic resin with a high refractive index, and a cladding 33 made of fluororesin with a low refractive index surrounding the core 32 (third
(shown in figure). The light is transmitted while being totally reflected at the boundary between the core 32 and the cladding 33. Note that the portion 34 of the bundle 3 that overlaps the liquid crystal 6 is roughened to allow internal light to leak. Furthermore, the edges 35 are treated to prevent light leakage.

A reflective tape 4 (40 mm x 100 mm) has a reflective surface 41 formed on its front side, and is adhered to the back side of the optical fiber bundle 3 with a transparent adhesive.

The light emitter 5 includes one green light emitting diode (not shown) built into a substantially cylindrical plastic case. The bundle 3 of optical fibers is attached to one side of the light emitter 5 so that light from the light emitting diodes enters the bundle 3. Moreover, a wire 51 for energization is taken out from the other side.

The liquid crystal 6 has a thin plate shape (1 mm x 40 mm x 100 mm) and is a transmissive type that uses a backlight. In addition, a large number of driving electrode pins 61 are arranged on the upper and lower sides 9. These electrode pins 61 are connected to a substrate 62 that drives the liquid crystal 6 in a time-division manner. 66 pieces of information are displayed. These displays can be visually recognized by forming the non-transparent portion 67.

Next, the effects of this embodiment will be described.

(1) The thickness of the optical fiber bundle 3 and the reflective chip 14 is extremely thin. Further, the light emitting device 5 can also be manufactured in a small size because it is easy to manufacture. Therefore, the thickness of the remote control case 1 can be reduced to half (15 mm) of the conventional case.

(2) The optical transmission loss of the optical fiber 31 is small (wavelength 5
Attenuation rate 500 dB/km at 50nm green
), a sufficient amount of light can be obtained with just one light emitting diode.

Next, a second embodiment of the present invention will be described with reference to FIG.

In this embodiment, the light transmission type liquid crystal display 2 has two light emitters 5.7.

The light emitting device 7 has a number of red light emitting diodes (r not shown) built therein.

In this embodiment, when the displayed value matches the actual value, the light emitter 7
The red light emission from the light emitter 5 stops and the light emission from the light emitter 5 switches to green light emission.

In this embodiment, since the illumination color of the liquid crystal 6 can be changed, the remote control using this display 2 can improve visibility.

Next, a third embodiment of the present invention will be described with reference to FIG.

In this embodiment, light enters the optical fiber bundle 3 from both sides. Also, in place of the reflective chi 14, the portion 3
The optical fiber bundle 3 on the back side of 4 is coated with reflective paint.

The display device 2 of this embodiment can illuminate the liquid crystal 6 even brighter. It also has the effect of making it difficult to cause a difference in brightness between the left and right sides.

[Brief explanation of drawings]

11] shows the first embodiment of the present invention, in which FIG. 2 is a structural diagram of a water heater remote control using a light transmission type liquid crystal display, FIG. 2 is a diagram showing the assembly of the display used in the remote control, and FIG. is a sectional view of the display. FIG. 4 shows a second embodiment of the present invention, and is a diagram illustrating the assembly of a light transmission type liquid crystal display. FIG. 5 shows a third embodiment of the present invention, and is a diagram illustrating the assembly of a light transmission type liquid crystal display. FIG. 6 is a structural diagram of a conventional water heater remote control. In the figure 2... Transmissive liquid crystal display 3... Bundle of optical fibers (optical fiber) 4... Reflective tape (opposite side) 5... Light emitter (light source) 6... Liquid crystal 63...
・Number 64...Character 65...Symbol 66...
Figure A...Water heater remote control

Claims (1)

[Claims] 1) A light-transmissive liquid crystal consisting of a transmissive liquid crystal that displays information such as numbers, characters, symbols, figures, images, etc. by time-division driving, and an illumination source arranged on the back side of this liquid crystal. In the display device, the illumination source uses a fiber surface light source that includes optical fibers bundled into a band shape and having a light leakage surface, a reflective surface formed on the back surface, and a light source attached to an end of the optical fiber. A light-transmissive liquid crystal display.